Syntactic Stitching II:Testing the rationalisation of the urban fabric as an intervention method in Cairo, Egypt

Self-generated informal settlements in Cairo are the product of incremental decisions which lead to a gradual aggregation of buildings that form urban blocks (Sioufi, 1981). The resulting block shapes and sizes may be suitable for meeting an individual’s needs for housing but may not meet the community’s needs for amenities that have a larger area. The street network is partially the product of building aggregation and therefore is unplanned and may not meet the community’s needs. This paper argues that minor urban interventions can be used to alleviate some of the issues that informal settlements face such as over-crowdedness and lack of access to the city.Based on previous work by Zied and Vialard in Cairo (2017) this study uses a two-pronged approach to develop a holistic intervention plan for informal settlements in Cairo, rationalizing the urban fabric by consolidating urban blocks to increase their resilience and optimizing the street network to improve connectivity and integration both within the settlement and to the wider urban fabric of Cairo. This type of informed intervention may improve community living standards and allow the settlement to develop into a functional neighbourhood that can be incorporated into the wider urban fabric.Based on measures tested and developed in the work of Colaninno et al in Barcelona (2011) and Song and Knaap in Portland (2007) this study firstly analyses self-generated urban blocks in terms of their shape and size, then explores how self-generated blocks can be consolidated. This study will then analyse the street network (Hillier and Hanson, 1989) then improve the syntactic structure of settlements and reconnect it to the city super-grid (Peponis et al., 2015). Interventions are developed and tested then compared to the initial state of the settlement to establish which is most beneficial to the settlement.The case studies selected are as follows:1. Informal Growth on agricultural land -Ard El Lewa, Dar El Salam2. Historic District –Mit Uqba and Medieval CairoThe methodology of this study uses two urban morphology measures; square compactness (Maceachren, 1985; Steadman et al., 2000) which measures the block’s deviation from a square, and elongation (Angel et al., 2010; Schumm, 1956) which uses the longest axis of the shape to measure its deviation from a circle. The urban block measures show the size and shape of blocks to assess their suitability and functionality in the urban fabric. The area and perimeter of the block will also be considered according to the proposed intervention. The axial analysis will be used to analyse the street network and visualise the integration core and syntactic structure of the settlement (Hillier, 1999; Hillier and Hanson, 1989) in order to rationalise the street network.Results indicate that minor interventions cause an acceptable improvement in the syntactic structure and block measures of the settlement, and can be enough to improve the settlement and reconnect it to the wider urban fabric. Urban blocks can be consolidated to accept functions which require a large area, but since the existing blocks often contain housing and streets create crucial access points, a holistic intervention plan (Levy, 1999) should be developed that consolidates blocks and widens and reroutes streets to improve the urban fabric without disrupting the existing structure